India raced past Germany last year to become the world’s fourth largest automobile market with sales of 4.02 million vehicles, behind China, US and Japan. What was particularly outstanding for India was its achieving the globe’s fastest rate of growth in automobile sales in 2017 at 9.5%. Indian manufacturers are all exporting cars in growing numbers taking advantage of skills availability and regulation built with galvanised steel, all the sub-INR 10 lakjh vehicles sold in the local market will have their panels made from CR steel with attempts to improve its anti-corrosive character through coatings and treatments. As field surveys conducted by IIT Bombay first in Mumbai in 2015 and then in Chennai earlier this year show, however advanced the coatings are, they are not found effective in stopping blisters, surface rust and perforations appearing on panels. Therefore, coatings are no substitute for hot-dip galvanised steel.
A major survey conclusion is that more than perforations, cars suffer damages by way of blisters, surface rust and imperfections as they get exposed to aggressive climate marked by high levels of humidity, marine environment and acid rain. More the cars age, greater will be the damages by corrosion, especially in their under-body and structural components. Over 60% of cars on Indian roads have surface-rust.
According to Sunil Duggal, CEO of Hindustan Zinc, “if Indian buyers are not insisting that their cars too should be made of galvanised steel, it is because of their lack of awareness.”
Interestingly, the source of inspiration for IIT work was the series of parking lot corrosion surveys of cars done in Detroit in Michigan in the 1980s at the behest of American Iron and Steel Institute and the Big Three US automakers – GM, Ford and Chrysler. Based on survey recommendations, the US automobile industry migrated from using CR steel to galvanised and galvannealed steel for making car interior, exterior and under-body parts. At the same time, much improvement continued to happen in base coat and clear coat paint technology, thanks to increasingly large R&D investments by Western and Japanese paints industry. A little known fact here is that consumer activists and government nudges played an important role in forcing the US automakers to use galvanised steel instead of CR steel.
Source : BUSINESS STANDARD
Yaang Pipe Industry Co., Limited (www.yaang.com)